期刊文献+
共找到89,314篇文章
< 1 2 250 >
每页显示 20 50 100
Generating functions for powers of second-order recurrence sequences
1
作者 王晓霞 李梅 《Journal of Shanghai University(English Edition)》 CAS 2011年第6期517-521,共5页
For the sequences satisfying the recurrence relation of the second order,the generating functions for the products of the powers of these sequences are established.This study was from Carlita and Riordan who began a s... For the sequences satisfying the recurrence relation of the second order,the generating functions for the products of the powers of these sequences are established.This study was from Carlita and Riordan who began a study on closed form of generating functions for powers of second-order recurrence sequences.This investigation was completed by Stnica.Inspired by the recent work of Istva'n about the non-closed generating functions of the products of the powers of the second-order sequences,the authors give several extensions of Istva'n's results in this paper. 展开更多
关键词 generating function second-order sequence the Binet formula
在线阅读 下载PDF
Molecular Identification of Echinococcus spp. and Other Taeniid Tapeworms Using Next-Generation Sequence Analysis of PCR Amplified 18s rRNA Gene
2
作者 Rasmi Abu-Helu George Kokaly +3 位作者 Sajeda Nojoum Imad Matouk Murad Ibrahim Ibrahim Abbasi 《American Journal of Molecular Biology》 2025年第1期75-87,共13页
Cystic echinococcosis (CE) is a prevalent zoonotic disease caused by Echinococcus granulosus, with a cosmopolitan distribution. The parasite is transmitted cyclically between canines and numerous intermediate herbivor... Cystic echinococcosis (CE) is a prevalent zoonotic disease caused by Echinococcus granulosus, with a cosmopolitan distribution. The parasite is transmitted cyclically between canines and numerous intermediate herbivorous livestock animals. Also, other Taeniid tapeworms could infect domestic dogs and they pose significant veterinary and public health concerns worldwide. This study aimed to develop a sensitive molecular method for detecting Echinococcus spp. DNA in dog fecal samples using next-generation sequencing (NGS). A set of PCR primers targeting conserved regions of Taeniid tapeworms’ 18s rRNA genes was designed and tested for amplifying genomic DNA from various tapeworm species. The PCR system demonstrated high sensitivity, amplifying DNA from all tested tapeworm species, with differences observed in amplified band sizes. The primers were adapted for NGS analysis by adding forward and reverse adapters, enabling the sequencing of amplified DNA fragments. Application of the developed PCR system to dog fecal samples collected from Yatta town, Palestine, revealed the presence of E. granulosus DNA in five out of 50 samples. NGS analysis confirmed the specificity of the amplified DNA fragments, showing 98% - 99% similarity with the 18s rDNA gene of E. granulosus. This study demonstrates the utility of NGS-based molecular methods for accurate and sensitive detection of Echinococcus spp. in dog fecal samples, providing valuable insights for epidemiological surveillance and control programs of echinococcosis in endemic regions. 展开更多
关键词 Cystic Echinococcosis Taeniid Tapeworms Next-Generation sequencing Molecular Detection Dog Fecal Samples
在线阅读 下载PDF
A Novel Property of Generalized Fibonacci Sequence in Grids
3
作者 YANG Zi-xian BAI Jian-chao 《Chinese Quarterly Journal of Mathematics》 2025年第1期103-110,共8页
Fibonacci sequence,generated by summing the preceding two terms,is a classical sequence renowned for its elegant properties.In this paper,leveraging properties of generalized Fibonacci sequences and formulas for conse... Fibonacci sequence,generated by summing the preceding two terms,is a classical sequence renowned for its elegant properties.In this paper,leveraging properties of generalized Fibonacci sequences and formulas for consecutive sums of equidistant sub-sequences,we investigate the ratio of the sum of numbers along main-diagonal and sub-diagonal of odd-order grids containing generalized Fibonacci sequences.We show that this ratio is solely dependent on the order of the grid,providing a concise and splendid identity. 展开更多
关键词 Generalized Fibonacci sequence Fibonacci identity Odd-order grid Geometric property
在线阅读 下载PDF
Chloroplast Genome Sequence Characterization and Phylogenetic Analysis of Pyrola Atropurpurea Franch
4
作者 Wentao Sheng 《Phyton-International Journal of Experimental Botany》 2025年第2期331-345,共15页
Pyrola atropurpurea Franch is an important annual herbaceous plant.Few genomic analyses have been conducted on this plant,and chloroplast genome research will enrich its genomics basis.This study is based on high-thro... Pyrola atropurpurea Franch is an important annual herbaceous plant.Few genomic analyses have been conducted on this plant,and chloroplast genome research will enrich its genomics basis.This study is based on high-throughput sequencing technology and Bioinformatics methods to obtain the sequence,structure,and other characteristics of the P.atropurpurea chloroplast genome.The result showed that the chloroplast genome of P.atropurpurea has a double-stranded circular structure with a total length of 172,535 bp and a typical four-segment structure.The genome has annotated a total of 132 functional genes,including 43 tRNAs,8 rRNAs,76 protein-coding genes,and 5 pseudo-genes.In total,358 SSR loci were checked out,mainly composed of mononucleotide and trinucleotide repeat.There are three types of scattered repetitive sequences,totaling 4223,including 2452 forward repeats,1763 palindrome repeats,and eight reverse repeats.The optimal codon usage frequency is relatively high with AT usage preference in this genome.Chloroplast genome comparative analysis in the family Ericaceae shows that the overall sequence is more complex,and there are more variations in the gene interval region.The collinearity analysis indicated that there is a complex rearrangement of species between different genera in Ericaceae.The selection pressure analysis showed that the protein-encoding genes rpl33 and rps16 were positively selected among the seven medicinal plants in Ericaceae.The maximum likelihood tree shows that the genetic relationship among P.atropurpurea,Pyrola rotundifolia,and Chimaphila japonica is relatively close.Therefore,an important data basis was provided for species identification,genetic diversity,and phylogenetic studies of P.atropurpurea and even this genus of plants. 展开更多
关键词 Pyrola atropurpurea chloroplast genome scattered repeat sequence collinearity analysis genetic relationship
在线阅读 下载PDF
Improving cutoff frequency estimation via optimized π-pulse sequence
5
作者 Wang-Sheng Zheng Chen-Xia Zhang Bei-Li Gong 《Chinese Physics B》 2025年第1期273-278,共6页
The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the π-pulse sequences(both equidistan... The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the π-pulse sequences(both equidistant and optimized)to a quantum probe coupled to a bosonic environment. To demonstrate the precision of cutoff frequency estimation, we theoretically derive the quantum Fisher information(QFI) and quantum signal-to-noise ratio(QSNR) across sub-Ohmic,Ohmic, and super-Ohmic environments, and investigate their behaviors through numerical examples. The results indicate that, compared to the equidistant π-pulse sequence, the optimized π-pulse sequence significantly shortens the time to reach maximum QFI while enhancing the precision of cutoff frequency estimation, particularly in deep sub-Ohmic and deep super-Ohmic environments. 展开更多
关键词 environment parameters estimation quantum Fisher information optimized p-pulse sequence
在线阅读 下载PDF
Relationship between pore throat structure and crude oil mobility of full particle sequence reservoirs in Permian Fengcheng Formation,Mahu Sag,Junggar Basin,NW China
6
作者 TANG Yong JIA Chengzao +8 位作者 CHEN Fangwen HE Wenjun ZHI Dongming SHAN Xiang YOU Xincai JIANG Lin ZOU Yang WU Tao XIE An 《Petroleum Exploration and Development》 2025年第1期112-124,共13页
Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the ... Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions. 展开更多
关键词 Junggar Basin Mahu Sag Lower Permian Fengcheng Formation full particle sequence reservoir pore throat structure crude oil mobility whole petroleum system
在线阅读 下载PDF
Mitochondrial targeting sequence of magnetoreceptor MagR:More than just targeting 被引量:2
7
作者 Yanqi Zhang Peng Zhang +10 位作者 Junjun Wang Jing Zhang Tianyang Tong Xiujuan Zhou Yajie Zhou Mengke Wei Chuanlin Feng Jinqian Li Xin Zhang Can Xie Tiantian Cai 《Zoological Research》 SCIE CSCD 2024年第3期468-477,共10页
Iron-sulfur clusters(ISC)are essential cofactors for proteins involved in various biological processes,such as electron transport,biosynthetic reactions,DNA repair,and gene expression regulation.ISC assembly protein I... Iron-sulfur clusters(ISC)are essential cofactors for proteins involved in various biological processes,such as electron transport,biosynthetic reactions,DNA repair,and gene expression regulation.ISC assembly protein IscA1(or MagR)is found within the mitochondria of most eukaryotes.Magnetoreceptor(MagR)is a highly conserved A-type iron and iron-sulfur cluster-binding protein,characterized by two distinct types of iron-sulfur clusters,[2Fe-2S]and[3Fe-4S],each conferring unique magnetic properties.MagR forms a rod-like polymer structure in complex with photoreceptive cryptochrome(Cry)and serves as a putative magnetoreceptor for retrieving geomagnetic information in animal navigation.Although the N-terminal sequences of MagR vary among species,their specific function remains unknown.In the present study,we found that the N-terminal sequences of pigeon MagR,previously thought to serve as a mitochondrial targeting signal(MTS),were not cleaved following mitochondrial entry but instead modulated the efficiency with which iron-sulfur clusters and irons are bound.Moreover,the N-terminal region of MagR was required for the formation of a stable MagR/Cry complex.Thus,the N-terminal sequences in pigeon MagR fulfil more important functional roles than just mitochondrial targeting.These results further extend our understanding of the function of MagR and provide new insights into the origin of magnetoreception from an evolutionary perspective. 展开更多
关键词 Magnetoreceptor(MagR) N-terminal sequence Mitochondrial targeting signal Iron-sulfur cluster
在线阅读 下载PDF
Intelligent extraction of road cracks based on vehicle laser point cloud and panoramic sequence images 被引量:1
8
作者 Ming Guo Li Zhu +4 位作者 Ming Huang Jie Ji Xian Ren Yaxuan Wei Chutian Gao 《Journal of Road Engineering》 2024年第1期69-79,共11页
In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs,this study presents an intelligent strat... In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs,this study presents an intelligent strategy for extracting road cracks.This methodology involves the integration of laser point cloud data obtained from a vehicle-mounted system and a panoramic sequence of images.The study employs a vehicle-mounted LiDAR measurement system to acquire laser point cloud and panoramic sequence image data simultaneously.A convolutional neural network is utilized to extract cracks from the panoramic sequence image.The extracted sequence image is then aligned with the laser point cloud,enabling the assignment of RGB information to the vehicle-mounted three dimensional(3D)point cloud and location information to the two dimensional(2D)panoramic image.Additionally,a threshold value is set based on the crack elevation change to extract the aligned roadway point cloud.The three-dimensional data pertaining to the cracks can be acquired.The experimental findings demonstrate that the use of convolutional neural networks has yielded noteworthy outcomes in the extraction of road cracks.The utilization of point cloud and image alignment techniques enables the extraction of precise location data pertaining to road cracks.This approach exhibits superior accuracy when compared to conventional methods.Moreover,it facilitates rapid and accurate identification and localization of road cracks,thereby playing a crucial role in ensuring road maintenance and traffic safety.Consequently,this technique finds extensive application in the domains of intelligent transportation and urbanization development.The technology exhibits significant promise for use in the domains of intelligent transportation and city development. 展开更多
关键词 Road crack extraction Vehicle laser point cloud Panoramic sequence images Convolutional neural network
在线阅读 下载PDF
The Application of Nicotiana benthamiana as a Transient Expression Host to Clone the Coding Sequences of Plant Genes
9
作者 Jianzhong Huang Peng Jia +3 位作者 Xiaoju Zhong Xiuying Guan Hongbin Zhang Honglei Ruan 《American Journal of Molecular Biology》 CAS 2024年第2期54-65,共12页
Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using co... Coding sequences (CDS) are commonly used for transient gene expression, in yeast two-hybrid screening, to verify protein interactions and in prokaryotic gene expression studies. CDS are most commonly obtained using complementary DNA (cDNA) derived from messenger RNA (mRNA) extracted from plant tissues and generated by reverse transcription. However, some CDS are difficult to acquire through this process as they are expressed at extremely low levels or have specific spatial and/or temporal expression patterns in vivo. These challenges require the development of alternative CDS cloning technologies. In this study, we found that the genomic intron-containing gene coding sequences (gDNA) from Arabidopsis thaliana, Oryza sativa, Brassica napus, and Glycine max can be correctly transcribed and spliced into mRNA in Nicotiana benthamiana. In contrast, gDNAs from Triticum aestivum and Sorghum bicolor did not function correctly. In transient expression experiments, the target DNA sequence is driven by a constitutive promoter. Theoretically, a sufficient amount of mRNA can be extracted from the N. benthamiana leaves, making it conducive to the cloning of CDS target genes. Our data demonstrate that N. benthamiana can be used as an effective host for the cloning CDS of plant genes. 展开更多
关键词 Coding sequence Genomic sequence Nicotiana benthamiana Plant Genes
在线阅读 下载PDF
A multi-scale second-order autoregressive recursive filter approach for the sea ice concentration analysis
10
作者 Lu Yang Xuefeng Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期115-126,共12页
To effectively extract multi-scale information from observation data and improve computational efficiency,a multi-scale second-order autoregressive recursive filter(MSRF)method is designed.The second-order autoregress... To effectively extract multi-scale information from observation data and improve computational efficiency,a multi-scale second-order autoregressive recursive filter(MSRF)method is designed.The second-order autoregressive filter used in this study has been attempted to replace the traditional first-order recursive filter used in spatial multi-scale recursive filter(SMRF)method.The experimental results indicate that the MSRF scheme successfully extracts various scale information resolved by observations.Moreover,compared with the SMRF scheme,the MSRF scheme improves computational accuracy and efficiency to some extent.The MSRF scheme can not only propagate to a longer distance without the attenuation of innovation,but also reduce the mean absolute deviation between the reconstructed sea ice concentration results and observations reduced by about 3.2%compared to the SMRF scheme.On the other hand,compared with traditional first-order recursive filters using in the SMRF scheme that multiple filters are executed,the MSRF scheme only needs to perform two filter processes in one iteration,greatly improving filtering efficiency.In the two-dimensional experiment of sea ice concentration,the calculation time of the MSRF scheme is only 1/7 of that of SMRF scheme.This means that the MSRF scheme can achieve better performance with less computational cost,which is of great significance for further application in real-time ocean or sea ice data assimilation systems in the future. 展开更多
关键词 second-order auto-regressive filter multi-scale recursive filter sea ice concentration three-dimensional variational data assimilation
在线阅读 下载PDF
Possible effects of selecting different station distributions in the optimal sequence estimation method
11
作者 Hao Ding 《Geodesy and Geodynamics》 EI CSCD 2024年第6期554-567,共14页
Since the inception of the optimal sequence estimation (OSE) method,various research teams have substantiated its efficacy as the optimal stacking technique for handling array data,leading to its successful applicatio... Since the inception of the optimal sequence estimation (OSE) method,various research teams have substantiated its efficacy as the optimal stacking technique for handling array data,leading to its successful application in numerous geoscience studies.Nevertheless,concerns persist regarding the potential impact of aliasing resulting from the choice of distinct station distributions on the outcomes derived from OSE.In this investigation,I employ theoretical deduction and experimental analysis to elucidate the reasons behind the immunity of the Y_(l'm')-related common signal obtained through OSE to variations in station distribution selection.The primary objective of OSE is also underscored,i.e.,to restore/strip a Y_(l'm')-related common periodic signal from various stations.Furthermore,I provide additional clarification that the‘Y_(l'm')-related common signal’and the‘Y_(l'm')-related equivalent excitation sequence’are distinct concepts.These analyses will facilitate the utilization of the OSE technique by other researchers in investigating intriguing geophysical phenomena and attaining sound explanations. 展开更多
关键词 Optimal sequence estimation Station selection GPS
在线阅读 下载PDF
Selection and application of wavelet transform in high-frequency sequence stratigraphy analysis of coarse-grained sediment in rift basin
12
作者 Ling Li Zhi-Zhang Wang +4 位作者 Shun-De Yin Wei-Fang Wang Zhi-Chao Yu Wen-Tian Fan Zhi-Heng Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第5期3016-3028,共13页
Wavelet transformation is a widely used method in high-frequency sequence stratigraphic analysis.However, the application is problematic since different wavelets always return the same sequence analysis results. To ad... Wavelet transformation is a widely used method in high-frequency sequence stratigraphic analysis.However, the application is problematic since different wavelets always return the same sequence analysis results. To address this issue, we applied five commonly used wavelets to theoretical sequence models to document some application criteria. Five gradual scale-change sequence models were simplified from the glutenite succession deposition by gravity flows to form the fining-upwards cycle sequences(FUCS) and coarsening-upwards cycle sequences(CUCS). After conducting theoretical sequence model tests, the optimal wavelet(sym4) was selected and successfully used with actual data to identify the sequence boundaries. We also proposed a new method to optimize the scale of continuous wavelet transformation(CWT) for sequence boundary determination. We found that the balloon-like marks in scalograms of db4, sym4, and coif4 wavelet determine, respectively, the fourth-order sequence boundary, the thick succession sequence boundaries in FUCS, and the thick succession sequence in FUCS and CUCS. Comparing the sequence identification results shows that the asymmetric wavelets had an advantage in high-frequency sequence boundary determination and sedimentary cycle discrimination through the amplitude trend of the coefficient, in which the sym4 wavelet is the most effective. In conclusion, the asymmetry of wavelets is the first selection principle, of which asymmetric wavelets are more sensitive to sediment deposition by flood flows. The match of the wavelet between the sequence is the second selection principle, in which the correlation of time-frequency impacts the accuracy of sequence surface localization. However, the waveform of the wavelet is a visual and abstract parameter for sequence boundary detection. The appropriate wavelet for lacustrine sequence analysis is the asymmetric wavelet with a weak number of side lobes. The depositional flows, depositional process,and autogenic are three sedimentary factors that influence the sequence analysis results. 展开更多
关键词 Wavelet analysis High-resolution sequence Sedimentary cyclicity Asymmetric wavelets
在线阅读 下载PDF
Pig pangenome graph reveals functional features of non‑reference sequences
13
作者 Jian Miao Xingyu Wei +6 位作者 Caiyun Cao Jiabao Sun Yuejin Xu Zhe Zhang Qishan Wang Yuchun Pan Zhen Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第3期956-970,共15页
Background The reliance on a solitary linear reference genome has imposed a significant constraint on our compre-hensive understanding of genetic variation in animals.This constraint is particularly pronounced for non... Background The reliance on a solitary linear reference genome has imposed a significant constraint on our compre-hensive understanding of genetic variation in animals.This constraint is particularly pronounced for non-reference sequences(NRSs),which have not been extensively studied.Results In this study,we constructed a pig pangenome graph using 21 pig assemblies and identified 23,831 NRSs with a total length of 105 Mb.Our findings revealed that NRSs were more prevalent in breeds exhibiting greater genetic divergence from the reference genome.Furthermore,we observed that NRSs were rarely found within coding sequences,while NRS insertions were enriched in immune-related Gene Ontology terms.Notably,our investigation also unveiled a close association between novel genes and the immune capacity of pigs.We observed substantial differences in terms of frequencies of NRSs between Eastern and Western pigs,and the heat-resistant pigs exhibited a substantial number of NRS insertions in an 11.6 Mb interval on chromosome X.Additionally,we discovered a 665 bp insertion in the fourth intron of the TNFRSF19 gene that may be associated with the ability of heat tolerance in South-ern Chinese pigs.Conclusions Our findings demonstrate the potential of a graph genome approach to reveal important functional features of NRSs in pig populations. 展开更多
关键词 Heat tolerance Immune ability Non-reference sequences Pig pangenome
在线阅读 下载PDF
Coordinated Control of Second-order Harmonic Voltage and Current Fluctuations in Cascaded H-bridge Inverter with Supercapacitor and DC-DC Stage at Variable Output Frequencies
14
作者 Ye Zhang Zixin Li +3 位作者 Fanqiang Gao Jinhao Zhang Cong Zhao Yaohua Li 《CES Transactions on Electrical Machines and Systems》 EI CSCD 2024年第4期481-492,共12页
In the cascaded H-bridge inverter(CHBI)with supercapacitor and dc-dc stage,inherent second-order harmonic power flows through each submodule(SM),causing fluctuations in both the dc-link voltage and the dc-dc current.T... In the cascaded H-bridge inverter(CHBI)with supercapacitor and dc-dc stage,inherent second-order harmonic power flows through each submodule(SM),causing fluctuations in both the dc-link voltage and the dc-dc current.There exist limitations in handling these fluctuations at variable output frequencies when employing proportional-integral(PI)control to the dc-dc stage.This paper aims to coordinately control these second-order harmonic voltage and current fluctuations in the CHBI.The presented method configures a specific second-order harmonic voltage reference,equipped with a maximum voltage fluctuation constraint and a suitable phase,for the dc-dc stage.A PI-resonant controller is used to track the configured reference.This allows for regulating the second-order harmonic fluctuation in the average dc-link voltage among the SMs within a certain value.Importantly,the second-order harmonic fluctuation in the dc-dc current can also be reduced.Simulation and experimental results demonstrate the effectiveness of the presented method. 展开更多
关键词 Cascaded H-bridge inverter(CHBI) DC-DC current reduction second-order harmonic fluctuation Variable frequencies Proportional-integral-resonant
在线阅读 下载PDF
Phylogenetic, phylogeographic and divergence time analysis of Anopheles subpictus species complex using ITS2 and COI sequences
15
作者 Lihini Sandaleka Muthukumarana Methsala Madurangi Wedage +1 位作者 Samanthika Rathnayake Nissanka Kolitha De Silva 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第5期214-225,I0004-I0038,共47页
Objective:To address the phylogenetic and phylogeographic relationship between different lineages of Anopheles(An.)subpictus species complex in most parts of the Asian continent by maximum utilization of Internal Tran... Objective:To address the phylogenetic and phylogeographic relationship between different lineages of Anopheles(An.)subpictus species complex in most parts of the Asian continent by maximum utilization of Internal Transcriber Spacer 2(ITS2)and cytochrome C oxidase I(COI)sequences deposited at the GenBank.Methods:Seventy-five ITS2,210 COI and 26 concatenated sequences available in the NCBI database were used.Phylogenetic analysis was performed using Bayesian likelihood trees,whereas median-joining haplotype networks and time-scale divergence trees were generated for phylogeographic analysis.Genetic diversity indices and genetic differentiation were also calculated.Results:Two genetically divergent molecular forms of An.subpictus species complex corresponding to sibling species A and B are established.Species A evolved around 37-82 million years ago in Sri Lanka,India,and the Netherlands,and species B evolved around 22-79 million years ago in Sri Lanka,India,and Myanmar.Vietnam,Thailand,and Cambodia have two molecular forms:one is phylogenetically similar to species B.Other forms differ from species A and B and evolved recently in the above mentioned countries,Indonesia and the Philippines.Genetic subdivision among Sri Lanka,India,and the Netherlands is almost absent.A substantial genetic differentiation was obtained for some populations due to isolation by large geographical distances.Genetic diversity indices reveal the presence of a long-established stable mosquito population,at mutation-drift equilibrium,regardless of population fluctuations.Conclusions:An.subpictus species complex consists of more than two genetically divergent molecular forms.Species A is highly divergent from the rest.Sri Lanka and India contain only species A and B. 展开更多
关键词 Molecular systematics ITS2 COI DNA sequences Phylogeny PHYLOGEOGRAPHY
在线阅读 下载PDF
On power series statistical convergence and new uniform integrability of double sequences
16
作者 Sevda Y■ld■z Kamil Demirci 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第3期519-532,共14页
In the present paper,we mostly focus on P_(p)^(2)-statistical convergence.We will look into the uniform integrability via the power series method and its characterizations for double sequences.Also,the notions of P_(p... In the present paper,we mostly focus on P_(p)^(2)-statistical convergence.We will look into the uniform integrability via the power series method and its characterizations for double sequences.Also,the notions of P_(p)^(2)-statistically Cauchy sequence,P_(p)^(2)-statistical boundedness and core for double sequences will be described in addition to these findings. 展开更多
关键词 power series methods statistical convergence uniform integrability double sequences
在线阅读 下载PDF
A cloud model target damage effectiveness assessment algorithm based on spatio-temporal sequence finite multilayer fragments dispersion
17
作者 Hanshan Li Xiaoqian Zhang Junchai Gao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期48-64,共17页
To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage p... To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage probability leveraging spatio-temporal finite multilayer fragments distribution and the target damage assessment algorithm based on cloud model theory.Drawing on the spatial dispersion characteristics of fragments of projectile proximity explosion,we divide into a finite number of fragments distribution planes based on the time series in space,set up a fragment layer dispersion model grounded in the time series and intersection criterion for determining the effective penetration of each layer of fragments into the target.Building on the precondition that the multilayer fragments of the time series effectively assail the target,we also establish the damage criterion of the perforation and penetration damage and deduce the damage probability calculation model.Taking the damage probability of the fragment layer in the spatio-temporal sequence to the target as the input state variable,we introduce cloud model theory to research the target damage assessment method.Combining the equivalent simulation experiment,the scientific and rational nature of the proposed method were validated through quantitative calculations and comparative analysis. 展开更多
关键词 Target damage Cloud model Fragments dispersion Effectiveness assessment Spatio-temporal sequence
在线阅读 下载PDF
The Upper Jurassic sediments,Marib-Shabwa Basin,Yemen:Lithofacies aspects and sequence stratigraphic analysis
18
作者 Mohammed Albaroot Mohamed M.Elhossainy +2 位作者 Nabil M.Al-Areeq Emad A.Abdullah Abdelhamid M.Salman 《Energy Geoscience》 EI 2024年第1期342-357,共16页
The present study is devoted to understanding the evolution of the Upper Jurassic Sab'atayn Formation in the Marib-Shabwa Basin,Yemen,through a sequence stratigraphic analysis based on integrating datasets of sedi... The present study is devoted to understanding the evolution of the Upper Jurassic Sab'atayn Formation in the Marib-Shabwa Basin,Yemen,through a sequence stratigraphic analysis based on integrating datasets of sedimentology,seismic sections,and well logs.The Sab'atayn Formation(Tithonian age)is represented by a series of clastic and evaporites that were deposited under fluvio-deltaic to prodeltaic settings.It is divided into four members including Yah(at the base),upwards to Seen,Alif,and Safir at the top.Two third-order depositional sequences were determined for the Tithonian succession which were separated by three sequence boundaries.These sequences were classified into their systems tracts signifying several sedimentation patterns of progradational,aggradational,and retrogradational parasequence sets.The first depositional sequence corresponds to the early-middle Tithonian Yah and Seen units that can be classified into lowstand,transgressive,and highstand systems tracts.The second sequence comprises the late Tithonian Alif unit that can be subdivided into transgressive and highstand systems tracts.The sandy deposits of the Alif Member(highstand deposits)represent the most productive hydrocarbon reservoir in the basin.The Upper Jurassic sediments in the study area were resulted from a combination of eustatic and tectonic effects. 展开更多
关键词 sequence stratigraphy Sandstone reservoir Well logs Upper Jurassic Marib-Shabwa Basin Yemen
在线阅读 下载PDF
Landscape of Sequence Variations in Homologous Copies of FAD2 and FAD3 in Rapeseed(Brassica napus L.)Germplasm with High/Low Linolenic Acid Trait
19
作者 Haoxue Wu Xiaohan Zhang +5 位作者 Xiaoyu Chen Kang Li Aixia Xu Zhen Huang Jungang Dong Chengyu Yu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第3期627-640,共14页
Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har... Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har-bors four and six homologous copies,respectively,of the two fatty acid desaturases FAD2 and FAD3,which con-trol the last two steps of ALA biosynthesis during seed oil accumulation.In this study,we compared their promoters,coding sequences,and expression levels in three high-ALA inbred lines 2006L,R8Q10,and YH25005,a low-ALA line A28,a low-ALA/high-oleic-acid accession SW,and the wildtype ZS11.The expression levels of most FAD2 and FAD3 homologs in the three high-ALA accessions were higher than those in ZS11 and much higher than those in A28 and SW.The three high-ALA accessions shared similar sequences with the pro-moters and CDSs of BnFAD3.C4 and BnFAD3.A3.In A28 and SW,substitution of three amino acid residues in BnFAD2.A5 and BnFAD2.C5,an absence of BnFAD2.C1 locus,and a 549 bp long deletion on the BnFAD3.A3 promoter were detected.The profile of BnFAD2 mutation in the two low-ALA accessions A28 and SW is different from that reported in previous studies.The mutations in BnFAD3 in the high-ALA accessions are reported for thefirst time.In identifying the sites of these mutations,we provide detailed information to aid the design of mole-cular markers for accelerated breeding schemes. 展开更多
关键词 Brassica napus linolenic acid FAD2 FAD3 promoter coding sequences mutation
在线阅读 下载PDF
Adaptive Successive POI Recommendation via Trajectory Sequences Processing and Long Short-Term Preference Learning
20
作者 Yali Si Feng Li +3 位作者 Shan Zhong Chenghang Huo Jing Chen Jinglian Liu 《Computers, Materials & Continua》 SCIE EI 2024年第10期685-706,共22页
Point-of-interest(POI)recommendations in location-based social networks(LBSNs)have developed rapidly by incorporating feature information and deep learning methods.However,most studies have failed to accurately reflec... Point-of-interest(POI)recommendations in location-based social networks(LBSNs)have developed rapidly by incorporating feature information and deep learning methods.However,most studies have failed to accurately reflect different users’preferences,in particular,the short-term preferences of inactive users.To better learn user preferences,in this study,we propose a long-short-term-preference-based adaptive successive POI recommendation(LSTP-ASR)method by combining trajectory sequence processing,long short-term preference learning,and spatiotemporal context.First,the check-in trajectory sequences are adaptively divided into recent and historical sequences according to a dynamic time window.Subsequently,an adaptive filling strategy is used to expand the recent check-in sequences of users with inactive check-in behavior using those of similar active users.We further propose an adaptive learning model to accurately extract long short-term preferences of users to establish an efficient successive POI recommendation system.A spatiotemporal-context-based recurrent neural network and temporal-context-based long short-term memory network are used to model the users’recent and historical checkin trajectory sequences,respectively.Extensive experiments on the Foursquare and Gowalla datasets reveal that the proposed method outperforms several other baseline methods in terms of three evaluation metrics.More specifically,LSTP-ASR outperforms the previously best baseline method(RTPM)with a 17.15%and 20.62%average improvement on the Foursquare and Gowalla datasets in terms of the Fβmetric,respectively. 展开更多
关键词 Location-based social networks adaptive successive point-of-interest recommendation long short-term preference trajectory sequences
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部